NCERT Exemplar Problems Class 6 Science – Garbage In Garbage Out

Question 1:
The method of preparing compost with the help of earthworms, is called
(a) composting (b) vermicomposting
(c) manuring (d) decomposing
Solution:
(b) Vermicomposting is a method of preparing compost with the help of earthworms. It is an excellent method of getting the best out of waste and also save a lot of money that is spent on buying expensive chemical fertilisers and manure from the market.

Question 2:
If you dump kitchen waste in a pit, it may, after sometime
(a) convert into compost
(b) convert into vermicompost
(c) remain as such
(d) remain forever in its dried form
Solution:
(a) The kitchen waste dumped in a pit may convert into compost after sometime. Kitchen waste is biodegradable and can be decomposed by microorganisms into compost, which is used as a manure. Compost is a natural fertiliser.

Question 3:
Which of the following activities does not reflect responsible behaviour with regard to waste disposal?
(a) Goods carried in paper bags or cloth bags
(b) Waste collected in polythene bags for disposal
(c) Waste separated into those that degrade and those that do not
(d) Making handicrafts with used up notebooks
Solution:
(b) Waste collected in polythene bags for disposal does not reflect responsible behaviour.
This is because polythene bags are non-biodegradable. They do not decompose in nature on their own and are eaten up along with garbage food by cattle, thus causing harm to them.

Question 4:
Paheli gave the following ill effects of the practice of burning dried leaves 1 and other plant parts
(a) Burning degrades the soil.
(b) Burning produces harmful gases/fumes.
(c) Precious raw materials to obtain manure at low cost is lost.
(d) Lost of heat is generated unnecessarily, f The correct reasons of why we should not burn leaves are
(a) i, ii and iv (b) i, ii, iii and iv
(c) ii and iii (d) ii, iii, and iv
Solution:
(b) The practice of burning dried leaves and other plant parts leads to all the ill affects mentioned above.
The best way to deal with this waste is to convert it into useful compost.

Question 5:
A garbage collector separate items mentioned below in the garbage into , red, green and blue containers for their transfer to landfill, composting
pit and recycling unit, respectively.
(i) Plastic bags (ii) Newspaper and journals
(iii) Screw and nuts (iv) Vegetable peels
(v) Metal chips (vi) Egg shells
Which item were transferred to which bin ?

Solution:
(c) The hazardous waste is dumped in red bin, i.e. plastic bags, screws and nuts and metal chips.
The organic waste is put in green bin, i.e. vegetable peels and egg shells. The recyclable material waste is thrown in blue bin, i.e, newspaper and journals.

Question 6:
The steps required for conversion of kitchen garbage into manure are given below in a jumbled form.
(i) Put garbage in a pit.
(ii) Cover the bottom of the pit with sand.
(iii) Cover the pit loosely with a gunny bag or grass.
(iv) Add worms.
Which of the following shows the correct sequence of the above steps?
(a) (ii), (i), (iv), (iii) (b) (i), (ii), (iii), (iv)
(c) (ii), (iv), (i), (iii) (d) (iv), (i), (ii), (iii)
Solution:
(a) The correct sequence of the steps are ii —> i —> iv —> iii.
This method of making manure from kitchen garbage using worms is called vermicomposting.

Very Short Answer Type Questions

Question 7:
Read the items mentioned in Columns I and II and fill in the related process in the Column III.

Solution:
(i) Vermicomposting
(ii) Garbage disposal/landfill
(iii) Recycling

Question 8:
Correct the definitions of certain terms given below by changing only one word.
(a) Compost Substances converted into manure for use in industries.
(b) Landfill Garbage buried under water in an area.
(c) Recycling Reuse of unused material in the same or another form.
Solution:
(a) Compost Substance is converted into manure for use in agricultural fields.
(b) Landfill Garbage is buried under soil in an area.
(c) Recycling Reuse of used material in the same or another form.

Question 9:
Provide the suitable term that expresses the meaning of each of the following statements.
(a) Greeting cards made from newspaper.
(b) Contents of the waste bins.
(c) Worms converting certain kinds of waste into manure.
(d) An area where a lot of garbage is collected, spread out and covered with soil.
Solution:
A suitable term describing/expressing the meaning of the above given statements are as follows:
(a) Recycling (b) Garbage
(c) Vermicomposting (d) Landfill

Short Answer Type Questions

Question 10:
To what use can you put the following kinds of garbage and how?
(a) Rotting smelly garbage
(b) Dry leaves collected in a garbage
(c) Old newspapers
Solution:
(a) Rotting smelly garbage can be converted into compost through composting. The process of converting plant and animal waste materials into manure by rotting is called composting.
(b) Dry leaves collected in a garbage can be used as manure by vermicomposting the method of making compost from dry leaves by using red worms is called vermicomposting.
(c) Old newspapers can be recycled to make paper bags or paper pulp for handicrafts. Recycling is the process of changing waste material into new products to reduce waste and pollution.

Question 11:
Paheli was writing a letter to her friend. She crumpled and threw the first draft of her letter on the floor as it had become untidy. Similarly, she crumpled and threw 6 more papers on the ground. In the end, she picked them up and put them in a polythene bag and threw it on the road outside her house.
Do you think, Paheli’s action were responsible? What would you have done if you were in her place?
Solution:
No, in my opinion, Paheli’s action were not responsible. She wasted paper and used a polythene bag. If I would have been in her place, I would have used the reverse side of the paper for doing rough work or convert it into paper pulp to make a handicraft item.

Question 12:
Read the poem written below and then answer the questions from the information gathered from the book or elsewhere.
Blue and Green
Two bins, you mean?
Yes, they are there
to throw your waste
But not in a hurry
Nor in a haste.
Select from waste, sieve if seems muddy Separate all items and when they are ready Place in a blue bin, or one that is green For a voyage to the landfill, or for composting.
(a) Name the two kinds of waste that need to be separated from each other in two different waste bins.
(b) Name two items of waste each that need to be sent to a (i) landfill (ii) for composting.
Solution:
(a) Two kinds of waste that need to be separated are biodegradable and non-biodegradable wastes. The former is part of garbage on which bacteria can act to form harmless substances and the latter is part of garbage that cannot rot or decay.
(b) (i) The part of garbage which cannot be disposed off by other method is dumped in a landfill, e.g. Any metal items.
(ii) The rotted plant and animal waste can be sent for composting. The microorganisms can act on these wastes to convert it into manure.

Question 13:
Beera, a farmer would clear his field everyday and burn dry leaves fallen on the ground. After sometime, he found that those people living in huts near his field were suffering from cough and breathing problems.
(a) Can you explain, why?
(b) Also suggest an environment friendly way to dispose the dry leaves.
Solution:
(a) Fumes and gases produced by burning dry leaves caused cough and breathing problems for the people living in the nearby area.
(b) An environment friendly way to dispose the dry leaves is to use them for making manure.

Long Answer Type Questions

Question 14:
Put a tick (✓) against the garbage items given in table which could be converted into manure. Put a cross (X) against the others.

Solution:
The given table shows garbage items that can be converted into manure or not.

Note: The biodegradable waste such as plant and animal waste can be converted into manure.

Question 15:
The pie charts A and B shown in the figure are based on waste seggregation method adopted by two families X and Y, respectively.

Which of the two families X or Y, do you think is more environmentally conscious and why?
Solution:
The family X is more environmentally conscious because they dispose off their kitchen waste and polythene bags separately.
Disposing them separately has an advantage as kitchen waste is biodegradable and can be converted into compost. Polythene bags on the contrary are non-biodegradable and cannot be recycled or decomposed.

Question 16:
Given below are steps in vermicomposting and each step has been given an alphabet. Rearrange the steps in the correct sequence and write the alphabets on the chart provided. One step is done for you.
F Dig a pit in a suitable place in your garden.
C Spread sand on the floor of the pit.
E Add vegetable peels and fruits waste in the pit.
A Sprinkle water to keep it moist.
D Place red worms in the pit.
B Cover with a gunny bag or grass.

Solution:
Vermicomposting is a method of composting where compost is made from biodegradable waste with the help of red worms.
The steps in this process are

Question 17:
Write three sentences on what comes to your mind when you get a chance to see the following:
(a) A rag picker
(b) A cow eating a polythene bag.
(c) Foul odour emanating from garbage at the entrance of your house.
Solution:
Following things come to our mind when we see:
(a) A rag picker
(i) Poor people working due to poverty.
(ii) He removes the garbage generated by others.
(iii) He is exposing himself to harmful substances, generated due to toxic waste.
(b) A cow eating a polythene bag
(i) Cow is getting exposed to hazardous materials, due to our mistake of using polythene bags.
(ii) There may be a possibility of polythene choking the animal to death.
(iii) Incorrect/Improper disposal of polythenes by us.
(c) Foul odour emanating from garbage at the entrance of our house
(i) There must be a large quantity of waste generated in the house.
(ii) The waste has made the surroundings unhealthy.
(iii) Unpleasant sight, the waste is disturbing the beauty of the house.

Question 18:
Beautiful handcrafted articles like boxes and toys are made up of paper pulp in our country. Can you explain how paper pulp which is made from paper can be used to make hard boxes and other articles?
Solution:
By following these simple steps, we can make hard boxes or other articles from the recycled paper pulp:
Step I Create a stencil by unfolding a small, one piece cardboard box and trace it on a piece of cardboard that is the same size as your mold. Then, cut out that shape with scissors.
Step II Place the box stencil between your mold and deckle
Step III Raise the mold, deckle and stencil to the surface in one continuous motion and then remove them from the pulp.
Step IV Remove the box from the stencil and let the paper dry.
Step V Assemble the box by folding and gluing or taping the edges. Decorate it as your need.

Question 19:
Recently, a ban on plastic bags has been imposed in many places. Is the ban justified? Give reasons in three sentences.
Solution:
The recent ban on plastic bags is justified because:
(i) The resources used to create the bags are scarce:
(ii) They harm the environment when disposed off improperly and also are visible blight of roadside litter.
(iii) Cost of disposing or recycling them is high, as they are non-biodegradable.

Question 20:
Why should we not bum plastic items?
Solution:
We should not burn plastic items because
(i) they do not burn easily.
(ii) they produce toxic gases when burnt and left over ashes are also toxic.
(iii) they add to soil pollution.
(iv) burnt pieces may be eaten by cows which may choke them to death.
(v) toxic gases lead to many respiratory diseases.

Question 21:
What happens when
(a) cooking medium is made to flow down a drain?
(b) insecticides, motor oil, paints are poured down the drain?
(c) tea leaves, cotton swabs and old soft toys are thrown into the drain?
Solution:
(a) If cooking medium is made to flow down a drain, It may clog pores in soil and can block pipes also.
(b) If insecticides, motor oil, paints are poured down the drain, this may kill useful microbes which help to purify water.
(c) If tea leaves, cotton swabs and old soft toys are thrown into the drain, it can choke the drains and block the water supply of the area.

Question 22:
Answer the following questions in one or two words or sentences.
(a) Why should we prefer to use paper bags rather than polythene bags?
(b) Who out of the following, should properly dispose of the garbage-father, mother, elder brother, younger sister?
(c) Which one out of beetles, roundworm and earthworm are used for vermicomposting and why?
Solution:
(a) We should prefer using paper bags rather than polythene bags as paper can be decomposed of easily. This reduce the generation of plastic garbage.
(b) Every member of the society or family is responsible to dispose of the garbage properly.
(c) Earthworms are the best organisms to be used for vermicomposting as they convert the waste from plants, animals or their products into compost.